Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2016

Stock-Based Compensation.

Schedule summarizing stock option activity under the 2001 Stock Plan, 2011 Stock Plan and 2015 Stock Plan

The following table summarizes stock option activity under the 2001 Stock Plan, 2011 Stock Plan and 2015 Stock Plan (in thousands):

	Number of
	Shares
	Underlying
	Options
Outstanding at December 31, 2015	5,701
Granted	1,601
Exercised	(1,074)
Canceled/forfeited/expired	(94)
Outstanding at September 30, 2016	6,134
Exercisable at September 30, 2016	3,486

Schedule summarizing the allocation of stock-based compensation

The following table summarizes the allocation of stock-based compensation in the accompanying condensed consolidated statements of operations (in thousands):

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2016		2015		2016		2015
Cost of sales	$	61	$	47	$	143	$	205
Selling, general and administrative		1,933		1,160		4,436		4,637
Research and development		657		345		1,538		1,489
Total	$	2,651	$	1,552	$	6,117	$	6,331

Schedule of the weighted-average assumptions used to estimate the fair value of options granted to employees

	Three Months Ended			Nine Months Ended
	September 30,			September 30,
	2016	2015		2016		2015
Risk-free interest rate	**	1.77	%	1.58	%	1.78	%
Expected dividend yield	**	0.0	%	0.0	%	0.0	%
Expected volatility	**	53.2	%	52.8	%	56.1	%
Expected term (in years)	**	6.06		6.05		6.07